1. Field of the Invention
The present invention relates to a suspension control apparatus having a dead zone setting circuit which can be switched to an inverted code control value when the polarity of an input signal is inverted within the dead zone at a first time.
2. Description of the Prior Art
A prior art suspension control apparatus has a dead zone setting circuit for maintaining a prior constant value before reaching a boundary value of a dead zone thereof after the polarity of an input signal is inverted as shown in FIG. 13, and then for switching to a constant value having different polarity from each other after reaching the boundary value.
In the prior art suspension control apparatus described above, when an input signal as shown in FIG. 8(A) is generated, it is changed over to a constant value with a different polarity at a boundary zone of its dead zone as indicated by dashed line in FIG. 8(D). Therefore, there has been such a problem that a delay in control is generated and a control value at the boundary zone of the dead zone is drastically changed, resulting in the generation of a shock. Then, in the case of canceling the dead zone, there is such a problem that the control value is hunting when its input value frequently varies in positive and negative polarities around zero point.